The present invention relates to a hydraulic actuating device for a cover and an associated lock for locking the cover in the closed position, comprising: a hydraulic cover actuator for moving the cover between an open position and a closed position, a hydraulic lock actuator for moving the lock between a locked position and an unlocked position, the cover actuator and the lock actuator each comprising a housing in which there is an actuator space, which accommodates a piston/piston rod assembly which can slide to and fro and has a piston rod which projects out of the housing on one side, the piston delimiting a base-side chamber and a rod-side chamber in the actuator space, the housing being provided with a first and second connection for supplying and discharging hydraulic fluid, which connections are respectively in communication with an associated first and second opening which adjoin the actuator space and, in each position of the piston/piston rod assembly, are respectively in communication with the base-side chamber and the rod-side chamber, a reservoir for hydraulic fluid, a pump with a delivery port for providing pressurized hydraulic fluid, a single actuable hydraulic valve for controlling both the cover actuator and the lock actuator. In particular, the invention relates to a vehicle of the convertible type provided with a cover and associated lock and also provided with a hydraulic actuating device of this type.
A hydraulic actuating device of the abovedescribed type is known, for example, from U.S. Pat. No. 5,253,575. In this known actuating device, the lock actuator is provided with a third opening, which is connected via an associated connecting line to the base-side chamber of the cover actuator. Furthermore, a single electromagnetic two-position valve is provided, for controlling both the lock actuator and the cover actuator.
A drawback of this known actuating device is that the lock must be of a specific type. In particular, the lock must be provided with an associated mechanical blocking device, which holds the lock in its unlocked position as long as the cover is open. When the cover is being closed, just before the closed position is reached, the cover comes into contact with this blocking device, with the result that the locking of the lock is eliminated and the lock can be moved into its locked position by the associated lock actuator. During the closing movement of the cover, the rod-side chamber of the lock actuator is continuously under pressure, but the blocking device prevents the movement of the lock actuator.
It is an object of the present invention to provide an alternative actuating device, which likewise only requires a single actuable hydraulic valve, but allows the use of a lock without a blocking device.
The present invention achieves this object by providing an actuating device of the abovedescribed type wherein the cover actuator is provided with a third opening which lies between the first opening and the second opening, and in that the third opening of the cover actuator is connected, via a first connecting line, to the second connection of the lock actuator, and the first connection of the cover actuator and the first connection of the lock actuator being connected to a common second connecting line, in which second connecting line the single actuable valve is accommodated, which in a first position connects the second connecting line to the reservoir and in a second position connects the delivery port of the pump to the second connecting line, and the second connection of the cover actuator being in communication with the delivery port of the pump.
Further advantageous embodiments and applications of the actuating device are described in the claims and will be explained in more detail below with reference to the drawing.